The area of flavins and flavoproteins is a broad, but clearly and simply defined one. It covers all aspects of work pertaining to the chemistry and biology of compounds based on the isoalloxazine nucleus and on a very few closely related structures. Because of the extraordinary and perhaps unique versatility of flavin as a prosthetic group and its involvement in a variety of important biological processes apart from simple oxidations and reductions, this area continues to expand rapidly. Interest in flavins ranges from theoretical chemistry to medical aspects. The Symposium will be one of a series which have been organized from 1965 onwards, the last having been in Ann Arbor, Michigan, in the summer of 1981. Because of the continued and increasing pace of research in this area, it seems important that regularly scheduled meetings should be held. Review lectures will cover the entire field and the meeting should bring together scientists from all over the world from a wide variety of disciplines, and promote valuable discussion and exchange of information. In addition, it should serve the purposes of keeping existing workers fully up-to-date with all aspects of the subject and of initiating intending new workers into this important area of research.